US239609A - hartman - Google Patents

Description

(No Model.) I 2 Sheets-Sheet 1.

J. M. HARTMAN. Device for Molding Tuyeres. No. 239,609. Patented April 5,1881.

Ina/e mi-nesse eets-Sheet 2,

(No ModelJ I 2 s J. M.-HARTMAN. V

Device for Molding .Tuyeres. i NO. 239,609. p Patented April-5,1881.

UNITED STATES JOHN M- HARTMAN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR ()F ONE-HALF TO LOUIS TAWS, OF SAME PLACE.

DEVICE FOR MOLDING TUYERES.

SPECIFICATION forming part of Letters Patent No. 239,609, dated A ril's, 1881.

Application filed January 21, 1881.

To all whom it may concern:

Be it known that I, JOHN M. HARTMAN, a citizen of Philadelphia, State of Pennsylvania, have invented an Improvement in Devices for Molding Tuyeres for Metallurgical Purposes, of which the following is a specification.

The object of this invention is to improve the molding of tuyeres, whereby better castings and a uniform thickness of metal are obtained.- I attain these objects by the means illustrated in the accompanying drawings, in which- Figure 1 shows a view of the butt-end of a tuyere-casting. Fig. 2 shows the double auchor. Fig. 3 shows a side view of pattern with the metallic rings around the butt-end, the flange double anchorsinserted in the nose, and the core-print 1). Figs. 4 and 5 show vertical sections of the mold for a tuyere with cores in position.

Similar letters refer to similar parts in all the drawings.

Tuyeres are generally cast with the nose or smaller diameter upward. In casting all the dirt and scoriae of the metal washes up into the nose of the tuyere, producing a spongy, porous casting, liable to leak water. The nose of the tuyere, being the most exposed part, must be of solid metal, perfectly water-tight, as any leakage of water will generate explosi ve gases or chill the hearth of the furnace. To obviate this I cast the nose down, and support the annular core f with double anchors. as per Fig. 2. These double anchors consist of a shank, a, a stem, b, a flange, c, and a double or L flange. d. placed at such a distance from the straight flange c as corresponds to the thickness of the metal in the nose of the tuyere. The straight flange c is made a littlelarger than the double flange, for the purpose of covering the hole in the pattern, as further shown, and to prevent the sand getting between the double flange and the straight flange 0 while molding. The

term double anchor is used to define the object of the L-shape flange, which holds the core in two different directions, and avoids the use of two single anchors,one of which would have to be set by hand.

The double anchors are cast of one length This double flange is, pattern. I.

(No model.)

and of the same material of the tuyeres. The

from chilling around them and forming a cold shot, which would leak water. The thinner the metal in the flanges the less heat will be abstracted from the molten metal while flowing around the anchors, and which will cause the molten metal to unite more firmly with them. The cross-section of the stem of the double anchor is reduced to a minimum of crushing strength, and the double flange on which the core rests is enlarged to give sufflcient bearing to the core and prevents its crushing. These cores are made of material easily crushed, which prevents the casting from cracking while shrinking in cooling. A large bearing-surface must therefore be provided, which I obtain by extending the double flange some distance beyond the stem of the anchor.

Just before molding a tuyere the anchors are rough-tiled on the stem and flanges, which 2, supports the annular core f, and also guides the core into position and retains it sidewise. The annular core is stiffened with hollow corerods g g, having holes a n a through them, by

which the gas is carried off from the core while the metal is being poured and set.

The annular rings j j, Fig. 4:, are formedin the mold by a metal ring, K, secured to the Sufficient taper must-be left between the rings j j for draft to draw the pat tern out of the mold readily. These metal rings are turned accurately round in a lathe on the faces j j, and produce a true-round surface in the mold and on the tuyere-castin g, which dispenses with the turning of the rings j j on the tuyere-castin g, as heretofore practiced.

Heretofore, in molding tuyeres, after the pattern was withdrawn from the mold anchors were placed in the mold by hand, which required great skill and time to get the anchors adjusted at the bottom and sides to keep the annular core central and at the proper distance from the bottom. If an anchor projects too i c fetches up against the nose of the pattern, the

pattern and anchors are set on the plate h, a flask is placed over the pattern, the top edge of which is of the same height as the top of the pattern, the mold is then rammed up with sand, and a parting-line struck at the top of the flask. (The cope of a flask is the npperor movable part of a flask.) The cope is then placed on the flask and rammed up also. On removing the cope it is found that the coreprints for the vent-pipes haveformed recesses in the cope for the vent-pipe. As the cope is about three inches deep and the core-prints are one and one-fourth inch high there is some sand left over the core-prints. A hole is then cut through the remaining sand above the coreprint, which allows the gas from the core to escape into the open air after the flask is closed and the metal poured. The tuyere-pattern is now removed from the mold, leavi ng the double anchors firmly in the mold and in exact position to set the annular core on them without further adjustment. The "ertical part of the double flange d guides the core into position, holds it firm sidewise, and thereby gives a uniform thickness of metal in the casting. The

core-printp having formed a recess in the bottom of the mold the central core, 0, is then placed in position. The cope is then placed on the flask and secured, when it is ready for pouring the metal to form the casting. The core surrounding the vent-pipes g g is made taper above the top of the tuyere for facility inclosing the top of the flask, which holds the core down, thereby preventing its floating up by the buoyancy of the molten metal. The core is thus held by the anchors below and the vent-pipes above. I do not confine myself to a particular angle between the two faces of the L flange of the double anchor, nor is it necessary that the two faces be joined at the corner, as they can be separate and be joined by a rib.

I do not claim a metallic band on a pattern, excepting so far as it relates to forming the taper rings 9" j in the mold direct. The taper rings can be formed by two separate metallic pieces inserted in the pattern, and having no metallic connection between them.

I am aware that tuyeres have been cast with the nose down, and heavy single anchors used to sustain the core in one direction; also, that true faces have been formed on castings by a separate core made in a core-box turned true. These 1 do not claim; but

What I do claim, and desire to secure by Letters Patent, is-

1. An anchor with a double or L -shape flange, forming a support and a guide to a core, for purposes herein specified.

2. In combination with a double anchor inserted in a pattern, a flange, c, to cover the hole in the pattern while molding, and to prevent the molding-sand from getting between the flange 0 and the double flange, as herein described.

3. The combination of a double anchor having an L-shaped flange, and the bottom plate, h, for supporting the anchors and cores, substantially as set forth.

JOHN M. HARTMAN.

Witnesses ROBERT C. GRAY, JAS. McLoUonLrN.

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